p. 25 - 39 MONOSPECIFIC CULTURE ISOLATION OF SOME PHYTOPLANKTONIC ALGAE OF NAPLES GULF Pia Elena Mihnea Institut Roumain de Recherches Marines Constanta Tullio Laurenzi Zoological Station Naples Abstract Taking into consideration the ecological and physyological requirements of planktonic and bentonic unicellular algae, a new method was established for isolation in monospecific cultures. For those organisms, that developed well on the solid media, Mulvany's microbial method (1969) was adapted.